This invention generally relates to electronic systems and in particular it relates to adjustable temperature-compensated threshold circuits.
The trip-points of threshold circuits typically lie within the given supply range in order to work properly. In today""s market, though, the need for multi-functional pins is becoming more necessary as the IC""s become increasingly pin and pad limited. With growing system integration and increasing silicon-packing densities, the package and its given pin-count become a limiting factor. As a result, the system can easily become pin limited.
A temperature compensated threshold circuit includes: a positive trip point circuit for providing a positive trip point when an input voltage is higher than a highest positive supply voltage; a negative trip point circuit for providing a negative trip point when the input voltage is below a lowest negative supply voltage; and a bias circuit for providing to the positive and negative trip point circuits a first current proportional to absolute temperature and a second current proportional to a base emitter voltage.